The present invention relates to a capsule for preparing a beverage or liquid food from a food substance which is brewed or extracted by using centrifuge forces exerted on a receptacle which contains the substance. The invention also relates to a system for carrying out the method.
It is known to prepare beverages wherein a mixture consisting of brewed coffee and coffee powder is separated with centrifugal forces. Such a mixture is obtained by bringing hot water and coffee powder together for a defined time. The water is then forced through a screen, on which screen powder material is present.
Existing systems consist of placing the coffee powder in a receptacle which is usually a non-removable part of a machine such as in EP 0367 600B1. Such devices have many disadvantages. Firstly, the coffee powder must be properly dosed manually in the receptacle. Secondly, the spinned coffee waste becomes dry and it must be removed by scraping the surface of the receptacle. As a result, the coffee preparation requires a lot of manual handling and is so very time consuming. Usually coffee freshness can also vary a lot and this can impact on the cup quality because coffee comes generally from bulk package or coffee is ground from beans in the receptacle itself.
Also, depending on the manual dosage of coffee and the brewing conditions (e.g., centrifugal speed, receptacle size) the cup quality can vary a lot.
Therefore, these systems have never reached an important commercial success.
In DE 102005007852, the machine comprises a removable holder into which an open cup-shaped part of the receptacle is placed; the other part or lid being attached to a driving axis of the machine. However, a disadvantage is the intensive manual handling. Another disadvantage is the difficulty to control quality of the coffee due to a lack of control for the dosing of the powder and a lack of control of the freshness of the coffee powder.
Other devices for brewing coffee by centrifuge forces are described in WO 2006/112691; FR2624364; EP0367600; GB2253336; FR2686007; EP0749713; DE4240429; EP0651963; FR2726988; DE4439252; EP0367600; FR2132310; FR2513106; FR2487661; DE3529053.
However, the effect of centrifugal forces to brew coffee or other food substances presents many advantages compared to normal “espresso” type brewing methods using high pressure pumps. In “espresso” types brewing methods, it is very difficult to master all the parameters which influence the quality of extraction of coffee. These parameters are typically the pressure, the flow rate which decreases with the pressure, the compaction of the coffee powder which also influences the flow characteristics and which depends on the coffee ground particle size, the temperature, the water flow distribution and so on.
Therefore, there is a need for proposing a new extraction process and a capsule adapted therefore for which the extraction parameters can be better and more independently controlled and therefore can be better mastered for controlling quality.
At the same time, there is a need for a method which is more convenient compared to the prior art centrifugal devices and which provides a better in-cup quality with a higher control of important quality parameters such as freshness and dosage in the receptacle.